AutoCAD .NET :: Passing Parameter To Batch File?

I got a problem to pass parameter from VB to batch file. My code is below to run the batch file and to pass parameter.

Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
Dim input As String
Dim output AsString
input = "C:atchFile est.gds"
output ="C:atchFile est.dxf"
Dim batchFile As String = "C:atchFileLC_gds2dxf.bat"
Process.Start(batchFile, input & ""& output)
EndSub

With this code the output is like below:

If you look at the screen shot you can find out that input and output variable is passing to one variable LC_gdsin. But I want that output file location will be assigned to LC_dxfout. I tried a lot but could not able to do that.

I am using VB2010 premium and windows 7 32 bit pc